|Publication number||US7781036 B2|
|Application number||US 11/672,722|
|Publication date||Aug 24, 2010|
|Filing date||Feb 8, 2007|
|Priority date||Feb 8, 2006|
|Also published as||CA2641028A1, CA2641028C, CN101378976A, CN101378976B, EP1991060A2, EP1991060A4, EP1991060B1, US20070184154, WO2007127519A2, WO2007127519A3|
|Publication number||11672722, 672722, US 7781036 B2, US 7781036B2, US-B2-7781036, US7781036 B2, US7781036B2|
|Inventors||Gary L. Gerbeling, Thomas C. Hoese, Scott Hemink, Gregory Holl, Anthony Gaylor|
|Original Assignee||General Mills Marketing, Inc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (9), Referenced by (1), Classifications (15), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application claims the benefit of priority under 35 U.S.C. 119(e)(1) of a provisional patent application Ser. No. 60/771,243 filed Feb. 8, 2006 which is incorporated herein by reference in its entity.
The invention relates generally to cooking by means of microwave energy, and more particularly relates to a system utilizing a flexible pouch for containing and cooking a food product which regulates and maintains an elevated internal heat and pressure during the microwave cooking process.
Preparing food products in a pouch is generally desirable. It permits the food product to be hygienically handled without direct contact with the food and it typically reduces or eliminates the need for cleaning cooking utensils. For example, it is known to boil a variety of foods including rice and pastas in net pouches. In doing so, the net pouch with rice or pasta is immersed into boiling water. After the food is cooked, the pouch is lifted out of the water. The pouch then acts as its own colander as the water drains from the food and out of the pouch through the spaces in the net.
The pouches described above are typically not used for certain types of food like vegetables or fish because cooking these types of food directly in water can result in the loss of vitamins and color from the food. The uptake of water can also result in a change in the structure of the product as well as in the product's overall flavor.
In response to the drawbacks caused by the direct exposure of certain foods to water during the cooking process, the “boil-in-bag” process has been developed. A boil-in-bag is a closed pouch which prevents contact between the food contained in the bag and the water along with the loss of vitamins and color described above. Moreover, boil-in-bag meals are often previously prepared cooked dishes in sauce which makes them unsuitable for being placed directly into water without any protective package. Such bags are very difficult to handle after boiling because the heat imparted due to the boiling is retained within the bag and may cause burns or other injury to the consumer when the bag is opened to access the food.
In response to the drawbacks of the boil-in-bag process described above, various types of disposable containers have been developed for use in heating or cooking foods in microwave ovens. For example, U.S. Pat. No. 4,961,944 to Matoba et al discloses a flexible pouch for use in cooking frozen foods. The food is filled into the pouch which is sealed and then frozen. The pouch has a number of holes covered by an adhesive strip. The adhesive strip is removed before microwaving to provide a vent for steam which is generated during the microwave cooking process.
Plastic containers having lids with pressure relief valves are also known such as disclosed in PCT Application PCT/CH98/00546. This application discloses use of a container having a tray and rigid cover. The cover has a pressure relief valve which opens and closes to maintain a predetermined pressure range for pressure cooking for fresh food in the container headed by a microwave. However, such packaging is relatively expensive and the shelf life for fresh foods is relatively short.
In view of the foregoing, there is a need for a low cost, low waste article and method of steaming frozen food products without encountering the drawbacks inherent in the prior art.
The invention generally includes a flexible pouch for use in microwave heating of frozen food that enables the product to be steamed during preparation. The pouch provides a predictable venting location, and is easily handled and opened when heating is complete. More specifically, the invention includes a flexible pouch for cooking a food item using microwave energy. The pouch includes a base configured to retain hot gases above atmospheric pressure within the pouch to heat and cook the food item when the package is exposed to microwave energy. The pouch also includes a cover comprising a sealant layer and a score layer. The score layer includes a weak portion which ruptures and vents the pouch at a predictable location when pressure within the pouch due to the hot gasses exceeds a predetermined pressure.
In an alternative embodiment, the invention includes a pouch meal including, a plurality of pieces of frozen food, a flexible pouch having an inner surface containing the food and an outer surface. The inner surface is defined by a base and a sealant layer. The base is configured to retain hot gasses above atmospheric pressure within the pouch to heat and cook the food when the pouch is exposed to microwave energy. The pouch also includes a score layer disposed over the sealant layer. The score layer includes a weak portion configured to rupture and vent the pouch at a predictable location when the pressure within the interior of the pouch due to hot gasses exceeds a predetermined pressure.
In yet another alternative embodiment, the invention includes a method of cooking a food item using microwave energy. The method comprises the steps of obtaining a pouch meal having a plurality of pieces of frozen food. The pouch has an inner surface containing the food and an outer surface, wherein the inner surface is defined by a base and a sealant layer. The pouch further includes a score layer disposed over the sealant layer. The score layer includes a weak portion configured to rupture and vent the pouch at a predictable location when the pressure within the interior of the pouch due to hot gasses exceeds a predetermined pressure.
The method also includes the step of cooking the food item with steam and hot gasses generated by heating the food item with microwave energy during a first phase of the cooking process. During this first phase of the cooking process, the sealant layer expands to hold the increased volume of hot gases until the sealant layer forms a permeable membrane. At this point, a second phase of the cooking process begins.
In the second phase of the cooking process steam and hot gasses are retained within the pouch by the base and score layer. Next, the pouch is ruptured at the weak portion of the score layer during a final phase of the cooking process.
During the final phase of the cooking process, the internal pressure of the pouch exceeds the predetermined pressure required to break the score layer at the weak portion to allow for release of excess pressure. Next, the method includes the step of venting some steam and hot gasses through the permeable sealant layer and weak portion of the score layer. Finally, some steam and hot gasses are retained within the pouch to complete the heating and cooking of the food item.
The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
A flexible pouch 10 in accordance with the invention is shown in
As shown in
With reference to
The combination of sealant layer 30 and base 12 defines interior 22. Score layer 28 is disposed against sealant layer 30. In one embodiment, score layer 28 is attached to sealant layer 30 with adhesive. In another embodiment. Score layer 28 may be thermally bonded to sealant layer 30.
Score layer 28 includes score 16. Score 16 does not extend to the sealant layer 30 of the cover 14, resulting in a completely sealed and enclosed pouch 10 containing food 24. In one embodiment, score 16 extends from a flange 26 on one side of the pouch 10 to another flange on an opposing side of the pouch. Score 16 may be mechanically formed in score layer 28. In alternative embodiments, score 16 may be chemically or thermally formed in score layer 28. By weakening the tensile strength of score layer 28 along score 16, score 16 provides a predictable rupture location along the score layer 28. In a one embodiment, the tensile strength of score layer 28 along score 16 is less than half the tensile strength of score layer 28 without score 16. In a preferred embodiment, the tensile strength of score layer 28 was measured to be approximately 17 lbs/in and the tensile strength of the score layer 28 along score 16 was measured to be approximately 7 lbs/in.
As shown in
As shown in the drawings, sidewall 18 is continuous, extending radially outwardly and upwardly from bottom 20 until terminating at flange 26. It should be recognized however that, in a preferred embodiment, the components of base 12 and cover 14 are highly flexible and can form a wide variety of shapes.
With reference to
When the microwave begins the cooking process, the pouch 10 generally comprises the cross sectional configuration shown in
As the cooking process continues, sealant layer 30 begins to stretch and deform to allow for increased volume on the interior 22 of the pouch 10 due to additional steam generation. At a second phase of the cooking process shown in
During a final phase of the cooking process, the pressure in the interior 22 of the pouch 10 exceeds a predetermined pressure causing the pouch to rupture at the weak portion of the score layer 28 as shown in
Once the cooking process is completed, the pouch 10 is removed from the microwave. In a preferred embodiment, the user removes the pouch 10 from the microwave by grasping the flange 26 on opposing sides of the pouch 10. The flange 26 provides a convenient and intuitive location on the pouch 10 for the user to hold. The location of the flange 26 relative to the food 24 enables the flange 26 to cool at a relatively rapid rate allowing the user to remove the pouch 10 from the microwave without discomfort.
With reference to
To create opening 50, the user grasps the flange 26 at locations transverse to the score 16. Using one hand to grasp point 42 and another hand to grasp point 44, the user pulls point 42 and point 44 apart. As the distance between point 42 and 44 increases, apertures 36, 38, and 40 expand to form a single opening 50. This configuration also provides a convenient location for the users hands away from the heat of any remaining steam that may be escaping from pouch 10. At this point, the food 24 can be easily removed from the container.
It is important to recognize that score 16 can be located in a variety of locations along score layer 28 while remaining within the scope of the invention. For example, in
With reference to
To create opening 50, the user grasps handles 56 and 58. Handles 56 and 58 are disposed near the flange 26 at locations transverse to the score 16. Using one hand to grasp handle 56 and another hand to grasp handle 58, the user pulls handle 56 and handle 58 apart. As the distance between handle 56 and handle 58 increases, apertures 52 and 54 expand to form a single opening 50. This configuration also provides a convenient location for the users hands away from the heat of any remaining steam that may be escaping from pouch 10. At this point, the food 24 can be easily removed from the container.
In another embodiment, pouch 10 may consist essentially of a cover 14. A score 16 is disposed in cover 14 to provide a predictable venting location. This embodiment has the advantage of simplifying the manufacturing process as only a single material is used to make the pouch 10.
Pouch 10 may be used for a variety of food items, including individually frozen predominately carbohydrate ingredients, individually frozen predominately vegetable ingredients, individually frozen predominately meat based ingredients, and combinations thereof, although a wide variety of food items may be used while remaining within the scope of the invention.
Although the invention has been described with reference to preferred embodiments, workers of ordinary skill will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4141487 *||Mar 29, 1977||Feb 27, 1979||Union Carbide Corporation||Disposable food package|
|US4691374||Feb 19, 1985||Sep 1, 1987||Golden Valley Microwave Foods Inc.||Cooking bag with diagonal gusset seals|
|US4961944||Sep 20, 1988||Oct 9, 1990||Gourmec Laboratory Co., Ltd.||Package for microwave oven cooking and method of use|
|US6596355 *||Jun 21, 2000||Jul 22, 2003||Dai Nippon Printing Co., Ltd.||Sealable package for heating in a microwave oven|
|US20020068668||Nov 30, 2001||Jun 6, 2002||Laser Machining, Inc.||Method for laser machining easy open, tear flexible packaging|
|CA2470054A1||Dec 13, 2002||Jun 26, 2003||Christian Fenn-Barrabass||Packaging and sealing tool for production thereof|
|EP0933310B1||Nov 13, 1998||Mar 31, 2004||DNP Technopak Tokai Co., Ltd.||Packaging bag for use in a microwave oven|
|EP1295807A1||Sep 14, 2001||Mar 26, 2003||Rabbit||Food package for use in microwave ovens|
|WO2003048001A1||May 13, 2002||Jun 12, 2003||Boon Chee Phee||Microwaveable package|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|WO2012170454A1 *||Jun 6, 2012||Dec 13, 2012||American Packaging Corporation||Microwavable film package having steam venting feature|
|U.S. Classification||428/35.7, 428/346, 428/483|
|International Classification||B29D22/00, B29D23/00, B32B1/08|
|Cooperative Classification||Y10T428/31797, Y10T428/1352, B65D2205/00, B65D81/3453, B65D2581/3427, Y10T428/2813, A23L3/362|
|European Classification||B65D81/34M1, A23L3/36D2|
|Feb 8, 2007||AS||Assignment|
Owner name: GENERAL MILLS MARKETING, INC., MINNESOTA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GERBELING, GARY L.;HOESE, THOMAS C.;HEMINK, SCOTT;AND OTHERS;SIGNING DATES FROM 20061031 TO 20061115;REEL/FRAME:018967/0830
|Jan 23, 2013||AS||Assignment|
Owner name: GENERAL MILLS, INC., MINNESOTA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GENERAL MILLS MARKETING, INC.;REEL/FRAME:029682/0075
Effective date: 20120711
|Feb 24, 2014||FPAY||Fee payment|
Year of fee payment: 4